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Data Scientist Interview Questions

Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.

9403
Questions
546
Companies
11
Topics
8
Languages

Showing 631–660 of 1971 results

  • DoorDashHardData Scientist
    Diagnose and experiment to reduce late deliveries

    This question evaluates a data scientist's competencies in causal inference, metrics engineering, data instrumentation and joining, root‑cause analysis, and experiment design focused on operational delivery performance.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Diagnose and reduce cold-food refund costs

    This problem tests the ability to diagnose root causes of operational cost drivers and design a rigorous experiment to validate potential mitigation policies.

    Analytics & ExperimentationTechnical ScreenCausal InferenceExperimentationMarketplace Analytics
  • DoorDashHardData Scientist
    Diagnose cold-food spike and design experiments

    This question evaluates a data scientist's skills in product analytics, metric design, diagnostics, causal inference, and experimental design for diagnosing cold-food complaint spikes using logs, GPS, weather and complaint labels.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Diagnose completed orders drop in Los Angeles

    This question evaluates a data scientist's competency in product analytics, causal inference, funnel and metric decomposition, segmentation, and experimentation for marketplace platforms, focusing on diagnosing sustained drops in completed orders.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Evaluate Account-Partner Onboarding with Success Metrics

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Evaluate Account-Partner Onboarding with Success Metrics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Evaluate Biker Feature Success

    This question evaluates experimentation and product analytics skills—metric design, causal inference, and marketplace impact assessment—in the context of a two-sided delivery marketplace, with attention to eligibility, routing, and matching effects.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Evaluate Courier-Selected Delivery Distance Limits

    This question tests your ability to design an A/B test for a marketplace feature while accounting for network effects, trade-offs between supply-side control and demand-side fulfillment, and selecting appropriate metrics.

    Analytics & ExperimentationOnsiteA/B TestingMarketplace AnalyticsCausal Inference
  • DoorDashHardData Scientist
    Evaluate Dasher Initiatives with A/B Testing and Metrics

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Evaluate Dasher Initiatives with A/B Testing and Metrics states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Evaluate Impact of $1 Fee on Fast-Food Profitability

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Evaluate Impact of $1 Fee on Fast-Food Profitability states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Evaluate Top-Dasher Program's Benefits and Challenges

    Evaluate Top-Dasher Program's Benefits and Challenges evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Evaluate a Bike Dasher Program with a Controlled Experiment

    Tests marketplace experimentation design, tackling spatial-temporal spillover effects, metric selection, and decision criteria for a multimodal courier fleet.

    Analytics & ExperimentationTechnical ScreenA/B TestingMarketplace ExperimentationCausal Inference
  • DoorDashMediumData Scientist
    Evaluate a Bike-Delivery Pilot with Marketplace Metrics

    This problem tests the ability to design an A/B test for a logistics marketplace, focusing on metric definition, experiment randomization strategy, and identifying potential confounding variables.

    Analytics & ExperimentationTechnical ScreenA/B TestingMarketplaceLogistics
  • DoorDashHardData Scientist
    Evaluate a new ranking model

    This question evaluates expertise in experimentation design and causal inference within two-sided marketplace environments. It tests the ability to handle interference, SUTVA violations, metric selection, and rollout safety when deploying ranking model upgrades — core competencies for data scientist roles focused on product analytics and A/B testing.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Experiment on increasing order notifications

    This question evaluates a data scientist's skills in experimental design, causal inference, metric definition and aggregation, power/MDE calculation, and cross‑channel attribution for order‑related messaging campaigns.

    Analytics & ExperimentationOnsite
  • DoorDashHardData Scientist
    Explain interest and influence stakeholders

    This question evaluates stakeholder management, cross-functional influence, data-driven decision-making, ownership, and the ability to reason about multi-sided marketplace dynamics for a Data Scientist role.

    Behavioral & LeadershipOnsite
  • DoorDashEasyData Scientist
    Find Monthly Top Customers Excluding High-Frequency Users

    This problem tests proficiency in window functions, filtering based on aggregated metrics, and handling ranking logic in SQL.

    Data Manipulation (SQL/Python)Technical ScreenSQLWindow FunctionsData Aggregation
  • DoorDashMediumData Scientist
    Generate Weekly Revenue and Engagement Summary with Pandas

    This question evaluates proficiency in data manipulation and analytics with Pandas and SQL, covering aggregations, distinct purchase counts, lambda-based user-tier classification, and platform-level conversion-rate computation.

    Data Manipulation (SQL/Python)Technical Screen
  • DoorDashMediumData Scientist
    How would you mentor junior teammates?

    A DoorDash Data Scientist onsite behavioral & leadership question that asks how you mentor others as a senior IC — especially more junior teammates. Strong answers diagnose each person's gaps, tailor support across levels and cross-functional partners, use concrete mechanisms (ramp plans, feedback rubrics, scalable templates, sponsorship), mentor through influence rather than authority, and measure effectiveness via independence and impact, all anchored in a detailed STAR example.

    Behavioral & LeadershipOnsite
  • DoorDashEasyData Scientist
    How would you test a bike delivery option?

    This problem tests the ability to design an A/B test, define success metrics, and account for confounding variables when introducing a new logistics channel (bike delivery) to a marketplace.

    Analytics & ExperimentationTechnical ScreenA/B TestingMetricsMarketplace Analytics
  • DoorDashMediumData Scientist
    Identify Challenges and Solutions for Bike-Delivery Program

    Evaluates operational and strategic thinking for a bike-delivery courier program. Strong answers identify marketplace, safety, weather, regulatory, courier, merchant, customer-experience, and unit-economics risks, then pair each challenge with practical mitigations and measurable rollout guardrails.

    Behavioral & LeadershipTechnical Screen
  • DoorDashHardData Scientist
    Identify Key Drivers of Delivery Decline in Los Angeles

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Identify Key Drivers of Delivery Decline in Los Angeles states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Investigate Causes of Cold Food Deliveries and Solutions

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Investigate Causes of Cold Food Deliveries and Solutions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Investigate Causes of Cold Meal Deliveries

    DoorDash data scientist case on cold meal deliveries, covering lifecycle timestamps, complaint metrics, segmentation, root-cause analysis, dispatch and packaging fixes, A/B testing, and marketplace guardrails.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Investigate Causes of Increased Driver Wait Time

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Investigate Causes of Increased Driver Wait Time states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Investigate Declining Successful Orders

    This question tests your ability to decompose a high-level drop in a key business metric into granular segments and formulate testable hypotheses to explain the underlying root causes.

    Analytics & ExperimentationTechnical ScreenProduct AnalyticsFunnel AnalysisHypothesis Testing
  • DoorDashHardData Scientist
    Investigate Falling Successful Orders

    This question evaluates a data scientist's ability to diagnose a drop in a product metric through anomaly verification, data validity checks, funnel and cohort analysis, causal attribution across marketplace sides (customer, restaurant, delivery), and experiment design.

    Analytics & ExperimentationTechnical Screen
  • DoorDashHardData Scientist
    Investigate Falling Successful Orders in LA

    This problem tests your ability to decompose a drop in a high-level business metric into granular segments, formulate testable hypotheses, and propose methodologies to identify the root cause.

    Analytics & ExperimentationTechnical ScreenRoot Cause AnalysisFunnel AnalyticsMarketplace Dynamics
  • DoorDashMediumData Scientist
    Investigate LA Order Drop

    This question evaluates marketplace analytics, causal inference, hypothesis-driven investigation, funnel decomposition, and experimentation design skills in a data science context.

    Analytics & ExperimentationTechnical Screen
  • DoorDashMediumData Scientist
    Investigate Pop-up Impact on Partner Referral Conversions

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Investigate Pop-up Impact on Partner Referral Conversions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite
  • DoorDashMediumData Scientist
    Measure Impact of Merchant Variety on Consumer Experience

    This interview question evaluates metric design, causal reasoning, experiment setup, diagnostics, SQL/statistical checks, and recommendations in a realistic interview setting. A strong answer for Measure Impact of Merchant Variety on Consumer Experience states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Analytics & ExperimentationOnsite